Treatment in gas distribution systems



April 6, 1943.

J. R. SKEEN TREATMENT IN GAS DISTRIBUTION SYSTEM Filed June 10, 19.39

Patented Apr. 6, 1943 UNITED STATES PATENT OFFICE 2,315,553 TREATMENT 1NGAS DISTRIBUTION SYSTEMS John R. Skeen, Philadelphia, Pa., assignor toThe i United Gas Improvement tion of Pennsylvania Company, a corpora-Application June 10, 1939, Serial No. 278,501 8 Claims (01. 48190) Thisapplication is a continuation-in-part of my copending application SerialNumber 236,822, filed Oct. 24, 1938, and pertains generally to thetreatment of the interiors of gas mains or other gas enclosures for thepurpose of sealing joints or laying dust, or both.

Systems for the distribution of gas include conduits or mains which areusually laid underground, and which comprise sections of pipe joinedtogether by means of welding, by means of packed Joints, by means ofscrew joints, or other- Wise.

The welded joint is a more recent development and is used chiefly toJoin pipe sections of steel or iron, other than cast iron. I

Older mains are usually made up of cast iron pipe sections joined bymeans of bell and spigot or other similar Joints. These joints areusually gpacked with hemp, jute, flax or other celluloslc material whichin turn is backed up with lead or cement or other material in a wellknown manner.

The lead or cement seal is tight and effective in preventing gas leakagewhen first applied but soon loses this quality due to expansion andcontraction of the main with change in temperature 'or for otherreasons. When this happens the efiectiveness of the joint in preventinggas leakage depends entirely upon the packing.

Generally speaking, there are two types of cel lulosic packing or yarnwhich have been used in Joints of gas mains or other gas enclosures.

At the time of their insertion in the joint, packing materials may beclassified as absorbent and non-absorbent in that the capacity of theformer to absorb water has not been impaired by special treatment,whereas such capacity of the latter has been purposely removed such asby treatment with tar.

These widely different types of packing may be referred to as "untarredand tarred respectively, and have widely different characteristics inservice. For instance, the untarred type of packing is capable ofabsorbing water which in turn swells the packing. This capacitycontinues until partially or wholly impaired by the accumulation of tar,resin and gum formed from constituents in the gas. the tar, resin andgum coating the packing. When this occurs the capacity of the. packingto take up and give off moisture with change in gas humidity isconsiderably reduced and the packing takes on the characteristics 01'the tarred type.

Until recently, when high pressure distribution has come into moregeneral practice, the bell and spigot or other joints packed with theuntarred type of packing gave very little trouble since the gasgenerally contained suificient moisture to keep the packing saturatedand, therefore, gastight.

However, when the gas is compressed to a high pressure for long distancedistribution in welded mains before being expanded to low pressure forlocal distribution, most of the water vapor (and some of the oils) arecondensed out. There is then no longer sufiioient water vapor in the'gaswhen expanded to the low pressure to keep the fibrous packing in thepacked joints in the low pressure mains moist. On the contrary, the gasis so dry that it rapidly draws out any absorbed moisture in the packingat a rate depending somewhat upon the accumulation of tar, resin andgum. However, the packing eventually dries out since the accumulation oftar, resin and gum is rarely capable of sealing moisture in the fibers.It follows that when the packing dries out serious leaks occur.

In other words, as long 'as the main is used for distributing ordinarymanufactured gas, and assuming that the untarred type of packing wasoriginally installed, very little trouble with joint leakage isexperienced. However, when the service is changed over to a manufacturedgas of lower moisture content, or over to natural gas which ischaracterized by a very low moisture content, or over to mixtures, thepacking dries out and shrinks sufliciently to cause the joint to becomeleaky.

While the use of the tarred type of packing avoids the absorption ofwater in the first instance, and consequent drying and shrinking shouldthe moisture content of the gas be lowered, nevertheless, the tarredtype of packing has not been wholly successful. This is thought to bedue in part to shrinkage in volume or cracking of the tar due to dryingor polymerization, and also in part to the necessity of swelling apacking in a joint to cause the packing to conform more exactly to thecontour of the joint and to reduce voids between the fibers.

Soap is sometimes applied to the untarred type of packing. Suchtreatment, however, does not prevent drying and shrinking.

Referring now to the problem of dust, it is to be noted that over aperiod of years the water condensed from wet gas together with otherconstituents of the gas such as carbon dioxide, hydrogen sulfide,hydrocyanic acid, naphthalene, and so forth, have in many instances,caused extensive corrosion of the interior walls of the mains. Theproducts of corrosion have accumulated on the walls of the mains and, inmany instances, large quantities have become disconnected and havecollected along the bottom.

Due to the presence of relatively large quantities of moisture, largelyresponsible for the corrosion in the first instance, the products ofcorrosion were maintained in a wet condition and did not tend to formdust in any appreciable quantity,

' Therefore, until high pressure distribution came into practice, andwhile the use of natural gas or natural gas mixtures was lesswidespread, very little difilculty was experienced with the formation ofdust in mains from the products of corrosion. V

In other words, as long as a main is used for distributing ordinary wetmanufactured gas very little trouble with dust resulting from corrosionis experienced. However, when the service is changed over to amanufactured gas of low moisture content, or over to natural gas ornatural gas mixtures which are characterized by very low moisturecontent, the moisture on and in the corrosion products dries out andsuch products become a serious source of dust.

The presence of considerable quantities of dust in the gas flowingthrough the mains of a distribution system is very undesirable becausedust tends to clog up customer service connections, interfer'es with theproper operation of meters, and tends to clog up burners and pilotoutlets.

Under extreme conditions, corrosion may be so severe as to form aserious obstruction in the main itself by reducing its effectivecross-sectional area such as by the accumulation of dust in piles in themain.

Since the corrosion products comprise not only ordinary iron rust butalso a variety of other compounds resulting from the action of hyrogensulflde, hydrocyanic acid, naphthalene, and other corrosive substances,the problem of wetting down the dust, of wetting the main wall, and ofthoroughly spreading a dust laying liquid becomes a major factor.

While the water miscible high boiling alcohols and water miscibleorganic oils are generally suitable for the purpose of laying dust asdescribed and claimed in copending applications, Serial Number 167,316,filed October 4, 1937, and Serial Number 208,729, filed May 18, 1938,both by Duncan 13. Williams, which have matured into Patents 2,167,140and 2,167,141, respectively, only three of the substances specificallyset forth in said applications are capable of swelling cellulosic fibrepacking to the same extent as water. With dry jute the volume increasecaused by the swelling is 44%.

I have discovered two additional substances namely, monomethyl ether ofethylene glycol and monomethyl ether of diethylene glycol which arecapable of swelling cellulosic fibre packing sufficiently to preventjoint leakage as described and claimed in my copending applicationSerial Number 128,555 filed March 1, 1937, now Patent 2,141,959 issuedDec. 27, 1938.

The percentage swelling of dry lute by a number of liquids is set forthin Tables 1 to 3:

TABLI 1 Substance Swelling Per ce nt Ethylene glycol 44 Diethyleneglycol 44 Monomethyl other of ethylene glycol" 38 Monomethyl ether ofdiethylene glycol 44 Glycerine 44 Tum: 2

Substance Swelling 12 Per cent T Monobutyl other of ethylene glycol '0Monobutyl other oi diethylene glycoL J; Monophenyl ether 01 ethyleneglycol. 0 Triethylene glycol l Monoethyl ether of triethylene glycol i.,2 Monomethyl amyl ether of ethylene glycol. 4 Monoethyl ether ofdiethylene glycol i6 Monoethyl ether of ethylene glycol 10 Turn 3Substance Swelling Per cent Mixed tar bases 0 Hexone. 3 Quinoline 4Octyl aldehyde 8 e 8 Triethyl benzene 9 Octyl aleoh 11 Olive oil i3Spindle oil 14 Benzaldehyde. 0 leic ac 3 Benzyl alcohol 0 Dimethylcyclic hexane] 0 Amyl acetate 4 Diethyl 0 Decahy o naphthalene 13' Anumber of liquids suitable for dust laying,

It should be noted that Table 4 includes not only the liquids of Table 1which alone are suitable fo swelling joint packing, but also liquids ofTable 2 as well as others which in themselves are not suitable forswelling joint packing.

All of the substances listed in Table l are of relatively low vaporpressure compared to water and are relatively inert in the presence ofthe swelling constituents of the gas. Each of them except glycerine israpidly absorbed by uncoated packing. Highly concentrated glycerine hasa viscosity which is somewhat too high for rapid absorption by thepacking. This quality, however, may be greatly improved as willhereinafter appear.

Likewise, all of. the substances of Table 4 are of low vapor pressurecompared to water and are relatively inert in the presence of the gas.

In many distribution systems, tar, resin, gum, and dust have beendeposited upon the packing and operate to exclude the substances listedin Table 1 from contact with the packing. In the case of packing whichsubstances, of course, are also excluded from contact with the packing.The substances of Table 1 are rather deficient as softening orsolubilizing agents for tar, resin and gum.

The tar, resin, and gum likewise prevent the materials of Table 4 fromreaching and wetting active sources and potential sources of dust, these-materials being likewise for the most part deficient as softening orsolubilizing agents.

A feature of this invention is to provide an improved leak proofingcomposition for swelling cellulosic packing in joints of gasdistribution systems which possesses sufficient solvent power withrespect to tar, resin and gum to cause the composition to be absorbed bythe packing with sufficient rapidity for practicable purposes.

Another feature of the invention is to provide an improved dust layingcomposition which possesses sufllcient solvent power with respect totar, resin and gum to cause the dust laying constituents of thecomposition to wet dust sources and to wet and be absorbed byaccumulations of dust with suflicient rapidity for practicable purposes.

Another feature of the invention is to provide a joint sealing and/0rdust laying composition having improved wetting qualities not only for tr, resin and gum, but also for cellulosic fibre and the metal of themain walls.

Another feature of the invention is-togprovide a, new article ofmanufacture and a DrOcess fOr making the same. i

Other features of the invention willbecome' more apparent to personsskilled in the art as the specification proceeds.

Generally speaking, the improvement in leak proofing compositionscomprises two or more muwas originally tarred, the

tually miscible liquids, one of which is especially adapted to beabsorbed by the packing and to swell the packing to at leastsubstantially the same extent as water; and the other of which isespecially adapted in) to soften or dissolve tar, resin and/or gum whichmay cover the packin and (b) to assist the spreading and climbing of theswelling agent in the joint packing. In the event that these two or moreliquids are not in themselves mutually miscible in the quantitiesemployed, a miscibility agent may be added. Such agent may comprise aliquid solvent in which the two or more liquids employed are soluble.

Examples of the first mentioned liquid of the leak proofing compositioncomprise any one or more of the substances listed in Table 1. suchsubstances being mutually miscible with each other.

Examples of the second mentioned liquid of the leakprooflng compositioncomprise, preferably with certain exceptions to be hereinafter noted.the arylamines.

Examples of miscibility agents suitable for ina para toluidine;

" ethylaniline; isoamylaniline;

corporation in leak proofing compositions to insure a single liquidphase are:

Methyl Carbitol (monomethyl ether of dlethylene glycol) Butyl Carbitolunonobutyl ether of diethylene Reference is made to my copendingapplication Serial No. 285,942, filed July 22, 1939, which describes andclaims the employment of a liquid mixture containing a non-cyclic highboiling aliphatic alcohol and monophenyl ether of ethylene glycol intreating the interior of a gas distribution system. Reference is alsomade to my copending application Serial No. 278,499, filed June 10,1939, which describes and claims the employment for the same purposes ofa liquid mixture containing a non-cyclic high boiling aliphatic alcoholand a ketone.

Referring now to dust laying compositions, generally stated, theimprovement comprises two or more mutually miscible liquids one of whichis adapted to wet, hold and/or bind dust particles and to coat dustsources; and the other of which is adapted (a) to soften ordissolve'tar. resin and/or gum which may cover dust'sources or formincrustations with dust deposits and (b) to assist the spreading andclimbing of the dust laying liquid upon the walls of the gas main andthroughout the sources of dust. In the event that these two or moreliquids are not in themselves mutually miscible in the quantitiesemployed, a miscibility agent may be added. Such agent may comprise aliquid solvent in which the two or more liquids employed are soluble.

Examples of the first mentioned liquid of the dust laying compositioncomprise any one or more of the substances listed in Table 4.

The second mentioned liquid of the dust laying composition comprises oneor more of the arylamines and particularly liquid arylamines. Althoughliquid arylamines are preferred, it is conceivable that solid arylaminesmay be employed, by dissolving the same on the treating liquid, withoutdeparting from the broad concept of the invention.

The'arylamines may be classified as follows:

(1) Aniline and its homologues.Examples of homologues areorthotoluidine; meta toluidine; 1.2,3-xylidine; 1,2,4-xylidine;1,3,2-xylidine; 1,3.4-xylidine; l-3-5-xylidine: 1,4.2-xylidine;commercial xylidine; 2,4,6-trimethylaniline mesidine); and2,4,5-trimethylaniline (pseudocumidine) (2) N-a7kyZanilinea-Examples aremonomethylaniline: dimethylaniline; mono-n-butylaniline:di-n-butylaniline; ethylaniline; methylbenzylaniline (a solid);methylbenzylaniline; phenyltrimethylammonium hydrox de; benzylamine:benzyldialkylamines; benzyltrimethylammonium hydroxide; andphenylethylamine.

(3) Acyl aryZamines.-Examples are acetanilide (a solid);acetoacetanildz: a solid); and phenylglycine (a solid.)

4) Polyaryl amines-Examples are diphenylamine (a solid); andtriphenylamine (a solid).

(5) Ari/l diamines.-Examples are orthophen- 'toluylenediamine (aarylamines which do not ylenediamine (a solid); metaphenylenediamine (asolid); paraphenylenediamine (a solid); 23-, toluylenediamine (a50116.); 2,4-toluylenediamine (a solid); 2,5-toluylenediamine (a solid);2,6-

solid) 3,4-toluylenediamine (a solid) 3,5-toluylenediamine (a solid) andthe dlamino naphthalenes (solids).

Examples of miscibility agents suitable for incorporation in dust layingcompositions to insure a single liquid phase are:

Methyl Carbitol Butyl Carbitol Monophenyl ether of ethylene glycolAcetone Diacetone alcohol Mesityl oxide Monophenyl ether of diethyleneglycol While the arylamines generally and particularly the liquidarylamines are especially suit able for tar, resin and gum cuttingpurposes in the case of mains having joints packed with cellulosic fibermaterial such as jute, I prefer to employ arylamines which have nodeleterious action upon the jute irrespective of whether the treatmentis for joint sealing purposes or solely for dust laying purposes.

I find that materials such as aniline appear to attack jute, whereasnuclear alkylated anilines such as the toluidines and the xylidinesevidence no such action whatsover. Apparently, the alkyl groups attachedto the ring prevent any disintegration of the jute.

Therefore, in the case of mains having joints packed with cellulosicfiber packing, I prefer to employ as tar resin and gum penetratingagents nuclear alkylated anilines, and particularly nuclear methylatedanilines since compounds with shorter alkyl groups appear to havegreater penetrating power, although other arylamines may be employedwithout departing from the broad concept oi the invention.

Likewise, in the case of joints packed. with other materials such asrubber, I prefer to employ as tar, resin and gum penetrating agentsattack such materials.

Any desired quantity of my tar, resin and/or gum softening and/orsolubilizing and wetting agent (referred to hereinafter and in theclaims for convenience as tar penetrating agent) may be added to thefiber swelling and/or dust laying liquid. I find, for example, that forordinary purposes from 5% to 20% is suflicient, but in extreme casessuch as when the packing is of the tarred type or large quantities oftar resin and/or gum have deposited from the gas that such largerquantities are preferably employed for example, up to say 70% or more.

Furthermore, the more treatments may be followed by a less drastictreatment or treatments such as the treatment for ordinary purposes.

Moreover, the main may be treated first with the tar penetrating agentand then with the dust laying and/ or joint sealing agent withoutdeparting from the spirit of the invention.

The presence of my tar penetrating agent greatly increases thedistribution of the treating liquid and its penetration through tar,resin, gum and dust incrustations and, therefore, not only greatlydecreases the time of treatment, but also greatly increases thethoroughness and effectiveness of the treatment when tar, resin, gumand/or dust incrustations are present.

I find that my tar penetrating agents do not drastic treatment orinterfere with the functions of other ingredients of the composition,and greatly enhance the spreading and climbing of the same.

Although the arylamines are not of a particularly corrosive character,if desired a suitable corrosion inhibitor, such as triethanolamine maybe added, of which amounts from 0.5 to 1.5% are examples.

Examples of liquid mixtures for both leakprooflng and dust laying are asfollows:

EXAMPLE 1 Per cent Diethylene glycol 65 Glycerine 15 Commercial xylidine20 EXAMPLE 2 Percent Diethylene glycol 65- Glycerine l3. 5Commercial'xylidine 15 conmiercial toluidine 5 Triethanolamine 1. 5

EXAMPLE 3 Per cent Glycerine 6 Commercial xylidine 40 The lattercomposition is rapidly absorbed by the cellulosic packing, whereas, whenglycerine gone is used the rate of absorption is rather It is to benoted that in the case of high viscosity liquids such as glycerine, mytar penetrating agents also serve to reduce the viscosity thus reducingthe time required for the composition to flow through the main whenapplied in this manner.

The foregoing are examples of liquid mixtures suitable for generalleakage treatment. when deposits or coatings of tar, resin and/or gumare excessive the following are more suitable in view of the increasedconcentration of the tar penetrating agent in the mixture. r

EXAMPLE 4 Per cent Glycerine 30 Commercial xylidine '70 EXAMPLE 5 Percent Diethylene glycol 30 Commercial toluidine 68 Triethanolamine 2EXAMPLE 6 Per cent Glycerine Commercial toluidine 68 Triethanolamine 2EXAMPLE 7 Per cent Diethylene glycol 30 Commercial xylidine 34Commercial toluidine 34 Triethanolamine 2 EXAMPLE 8 Per cent Diethyleneglycol 30 Commercial xylidine i 68 Triethanolamine 2 ExAurLn 9 Per centDiethylene glycol 25 Glycerinc 25 Commercial toluidine 48.5Tiiethanolamine 1. 5

Generally speaking, any other liquid or combination of liquids of Table1 may be substituted for diethylene glycol or glycerine in the aboveexamples and any other arylamine which does not attack cellulosicfibrous packing or any combination of such arylamines which does not attack cellulosic fibrous packing may be substituted, preferably using amiscibility agent when necessary to form a single liquid phase, which ispreferred to a plurality of liquid phases, although it is conceivablethat the latter may be employed without departing from the broadconcjcpt of the invention. Examples of liquid mixtures suited moreparticularly for dust laying only are as follows:

EXAMPLE 1 I Per cent Commercial xylidine 20 Monophenyl ether of ethyleneglycol 50 Diethylene glycol 30 EXAMPLE 2 Per cent Commercial toluidinel5 Dibutyl phthalate 75 Monomethyl ether of diethylene glycol 10 EXAMPLE3 Per cent Commercial xylidine 20 Propylene glycol '10 Monobutyl etherof diethylene glycol l ExAMPLn 4 Per cent ,Diethylene glycol 20Monophenyl ether of ethylene glycol 50 Monomethyl ether of diethyleneglycol 10 Commercial toluidine 20 EXAMPLE 5 Per cent Diethylene glycol50 Monophenyl ether of ethylene glycol 20 Diglycol iaurate Commercialxylidine 10 Commercial toluidine 10 Generally speaking, any other liquidor combination of liquids of Table 4 may be substituted for the dustlaying liquid or liquids in the above examples. Likewise, any otherarylamine or any combination of such arylamines may be substituted,preferably using a miscibility agent or other means such as forming anemulsion when necessary to form a single liquid phase, which ispreferred to a plurality of liquid phases, although it is conceivablethat the latter may be employed without departing from the broad conceptof the invention.

The treating liquid may be applied to the interior surface of a pipesection and/or to the packing in a joint before, during or after theassembly oi the pipe sections to form the main. This may be accomplishedin any desired manner such as by dipping, spraying, brushing, orotherwise.

If the main is already in service, sections of the main may be blockedoff by means of inflated bags or other means, and the sections thencompletely filled with the liquid after which the liquid can be drawnoil and re-used.

On the other hand, the liquid maybe sprayed into the gas by the foggingprocedure earlier mentioned so that the packing and/or dust sourcesabsorb the liquid from the gas stream or, in other words, so that theliquid is deposited from the gas stream onto the packing and/or onto thesources of dust.

In another method of application the liquid is introduced into the mainat high points and allowed to run by gravity to low points where theexcess can be drawn off. An examination of mains treated in this mannershows that my compositions have greatly improved climbing properties.

Another method comprises inserting a long length of hose into the mainwith a spray at its end, or with a plurality of sprays distributed alongits length, and pumping the treating liquid into the hose whilewithdrawing the hose either continuously or intermittently or otherwise,or while the hose remains stationary.

In the last three methods of application service on the line need not beinterrupted. The packing becomes impregnated with the composition anddust sources become coated with the treating liquid. The wetting offinely divided material causes it to be bound together in a mass whichprevents it from rising in a dust regardless of the velocity of the gastraveling through the main. The clogging of mains, meters, regulatorsand appliances is thus eifectively prevented.

A typical gas main is illustrated in the drawing in which:

Figure 1 is a side elevation, partly in section, illustrating a gasmain; and

Figure 2 is a cross-section on line 2-2 of Figure 1. 1

In the drawing the gas main in is shown with a joint comprising bell IIand spigot l2 fitting within said bell and spaced therefrom In the spacebetween the bell and the spigot is celluloslc fibre-packing l 3 whichmay be tarred or untarred and a seal 14 of lead or other suitablematerial for holding the packing in place. The treating liquid l5 asillustrated is being run through the main by gravity. It contacts thebottom of the main and any deposits accumulated thereon. It alsocontacts the packing at space l6 which space is left between the spigotand the shoulder of the bell to provide for expansion and contractiondue to temperature changes. The packing absorbs the liquid at 16 and theliquid climbs and is carried up in the packing as shown by the outergroup of arrows in Figure 2. If a substance of Table 1 is present thepacking is swollen to subliquid to the packing and/or to the interior ofthe conduit may be employed. For instance, in case of very largediameter mains the level of the liquid l5 may be raised or may be madeto fill the entire main if desired, or the spray or fogging methods maybe employed.

In the case of a welded main, or other main having joints in whichcellulosic fibre packing is not present, the treatment becomes primarilyone of dust laying. Likewise, when the liquids of Table 4 other thanthose of Table 1 are employed the treatment becomes more essentially oneof dust laying regardless of the type of main treated.

The terms comprises and comprising are used in the claims in theirusually accepted meanings which do not exclude other steps or thepresence of substances other than those specifically recited.

While the invention has been described in connection with gas mains, itis to be understood that it is applicable to any part of a gasdistribution system wherein similar problems may arise. It is also to beunderstood that the various agents referred to herein may be used eitherin the pure or commercially pure form, or in any other suitable formincluding the commercial and crude forms.

It is to be understood that the above particular description is by wayof illustration and that changes, omissions, additions, substitutions,and/r modifications, might be made within the scope of the claimswithout departing from the spirit of the invention.

I claim:

1. A method for treating the interior of a gas distribution system whichcomprises applying to the interior of said system a liquid mixturecomprising a non-cyclic high boiling aliphatic alcohol and a nuclearlymethylated aniline.

2. A method for reducing gas leakage through cellulosic fibrous packingin a joint of a gas distribution system, comprising impregnating saidpacking with a cellulosic fiber swelling agent selected from a groupconsisting of ethylene glycol, diethylene glycol, monomethyl ether ofethylene glycol, monomethyl ether of diethylene glycol and glycerine bybringing said agent into contact with said packing in the presence of anuclearly methylated aniline.

3. A method for laying dust in the interior of a gas distribution systemhaving dust sources, comprising enveloping said dust sources with a dustlaying liquid selected from a group consisting of ethylene glycol,diethylene glycol, monomethyl ether of ethylene glycoLmonomethyl etherof diethylene glycol, and glycerine by bringing said liquid into contactwith said dust sources in the presence of a nuclearly methylatedaniline. 4. A method for rejuvenating cellulosic pack ing such as juteand hemp in a joint of a gas distribution system to reduce gas leakageat said joint, which comprises contacting said packing with a liquidmixture comprising commercial toluidine and at least one of a groupconsisting of ethylene glycol, diethylene glycol, monomethyl ether ofethylene glycol, monomethyl ether or" diethylene glycol, and glycerine.

5. A method for rejuvenating cellulosic pack-= ing such as jute and hempin a joint of a gas distribution system to reduce gas leakage at saidjoint, which comprises contacting said packing with a liquid mixturecomprising commercial xylidine and at least one of a group consisting ofethylene glycol, diethylene glycol, monometh t l ether of ethyleneglycol, monomethyl ether of diethylene glycol, and glycerine.

6, A joint in a gas distribution system cornprising spaced cooperatingelements, cellulosic fibrous packing such as jute between saidcooperating elements positioned to form a seal, and a liquid mixtureabsorbed by said packing, said liquid mixture comprising at least one ofa group consisting of ethylene glycol, diethylene glycol, monomethyl.ether of ethylene glycol, monomethyl ether of diethylene glycol, andglycerine and at least one of a group consisting of orthotoluidine,meta-toluidine, para-toluidine, 1,2,3- xylidine, 1,2,4-xylidine,1,3,2-xylidine, lBA-Xyltdine, 1,3,5-xylidine, and 1,4,2-Xylidine.

7. A method for treating the interior of a gas distribution system whichcomprises applying to the interior of said system a liquid mixture comprising a non-cyclic high boiling aliphatic alcohol, and an arylamine.

8. A gas conduit having interior dust sources wetted down with a liquidmixture comprising a non-cyclic high boiling aliphatic alcohol, and anarylamine.

JOHN R. SKEEN.

